1. Field of the Invention
The present invention relates to a device for electronic data storage. More particularly, the present invention relates to a magnetic media data storage component having one or more independent hard drives in a stacked or layered configuration that are hermetically sealed within a housing suitable for mounting to a circuit board. The hard drives can be controlled by a single hard drive controller located inside or outside the housing.
2. Description of Related Art
Digital data may be stored electronically on a number of different types of media such as magnetic media. A popular form of magnetic storage media are hard drives. Hard drives are electronic components that are typically installed into larger computer systems. The function of a hard drive is to store digital data generated by a computer so that it can be recalled at a later time by the computer.
A hard drive exchanges data with a computer system""s central processing unit (xe2x80x9cCPUxe2x80x9d). Before data from the CPU is stored on a hard drive, the data is first processed by an electrical component called a hard drive controller. The hard drive controller provides an interface between the hard drive and the CPU that is necessary to determine where and how data will be stored on the hard drive. If more than one hard drive is incorporated into a single computing device, then one hard drive controller is necessary for each hard drive.
Hard drives typically are housed within rigid metallic housings. Included in the hard drive housing is an electronic circuit board onto which the hard drive""s electrical components are mounted. The magnetic media onto which data is stored within a hard drive consists of a rigid disk coated with a magnetic material. These rigid disks are referred to in the art as platters. The platter is oriented in the disk drive such that it rotates about a central axis in the same manner as a phonograph or record rotates on a turntable. The rotation of the platter is driven by a high speed electric motor.
A component called a read/write head transfers data to, and from, the platter. The read/write head reads data from the platter by sensing the magnetic fields on the platter. The read/write head writes data to the hard drive by inducing a magnetic field which is recorded on the platter. The read/write head is located at the end of an armature. The armature controls the position of the head relative to the platter. As the armature moves, the read/write head is guided over different positions on the platter. The movement of the armature can be controlled by a high-speed linear motor.
The read/write head does not contact the platter. Rather, a small air gap separates the read/write head from the platter. The gap is maintained by the aerodynamic forces exerted on the read/write head as the platter rotates and causes the air between the platter and read/write head to move. In effect, the read/write head flies above the surface of the platter. Therefore, air must be present inside the hard drive to maintain the aerodynamic forces on the read/write head. If the air pressure within the hard drive housing fluctuates, the gap between the read/write head could close, and the read/write head could contact the platter. If the read/write head contacts the platter, both the read/write head and the platter could be damaged significantly and data could be lost. To avoid fluctuations in air pressure in the hard drive housing, most hard drives are equipped with an air vent which allows for the exchange of air between the hard drive and the environment.
The size of a hard drive can vary. For example, a hard drive for use in a laptop computer may be the size of a deck of playing cards. Other hard drives may be much larger, depending on the design of the hard drive, the application in which it is used and the storage capacity of the hard drive. However, as the demand for faster, more powerful and more compact computers and computing products has increased, the demand for more compact hard drives also has increased. In addition, as computer processors advance in speed and capability, data storage requirements also increase. Therefore, compact hard drives with increased storage capacities are also in high demand.
Several methods have been used to provide more compact hard drives with increased storage capacities. For example, some hard drives feature multiple platters and multiple read/write heads. Other hard drives allow the read/write head to store data on the upper and lower surfaces of each platter in the hard drive. In some applications, several individual hard drives may be connected together by cables in serial sequence to expand storage capacity.
Most compact hard drives have been packaged as modules that are removable from the computer system into which they are installed. PCMCIA and Compact Flash are formats for removable hard drives used, for example, in laptop computers. Other compact hard drives are installed into the computer system and are not intended to be removed from the system. These drives are often mounted to the chassis of the computer system. Wires or ribbon cables connect these drives to the hard drive controller and to the CPU of the computer system into which they are installed.
The hard drives described above have several disadvantages. One disadvantage of hard drives known in the art is that they require special ports and cabling to connect them with the computer systems into which they are installed. These hard drives are not designed for convenient mounting onto a circuit board for use in embedded computers or portable electronics. For example, removable hard drives such as the PCMCIA or Compact Flash hard drives require special ports and connectors to integrate them into computer systems. These ports and connectors consume space in the computer system. Compact hard drives that are permanently installed in computer systems utilize ribbon cables to connect each hard drive to each hard drive controller and central processing unit. These cables complicate installation of the hard drives and other computer components, and consume space in the system.
Another disadvantage of hard drives known in the art is that they are vented to maintain the air pressure in the hard drive housing so that the read/write head flies above the platter. As air passes through these vents, micro-particles such as dust and spores and other contaminants also enter the hard drive housing. Therefore, vented hard drives are not suitable for use in micro-particle contaminated environments. In addition, vented hard drives cannot operate in high or low pressure environments because the air pressure within the hard drive housing fluctuates with the air pressure of the environment. If a hard drive is operated in a low air pressure environment, for example, the air gap between the read/write head and the platter could close, resulting in damage to the hard drive and data loss.
Another disadvantage of the hard drives known in the art is that if several hard drives are to be installed in a computer system, one controller for each hard drive also must be installed into the system, which is costly and space consuming.
Therefore, it is one object of the present invention to provide a hard drive component for electronic data storage that can be mounted directly to a circuit board in the same fashion that other electrical components are mounted to circuit boards.
It is another object of this invention to provide a hard drive component for electronic data storage that is capable of operating in environments in which micro-particle contaminants are present.
It is another object of this invention to provide a hard drive component for electronic data storage that is capable of operating in a high or low air pressure environment.
It is another object of this invention to provide a hard drive component for electronic data storage that is compact and has increased storage capacity.
It is yet another object of this invention to provide a hard drive component for electronic data storage in which several hard drives are combined into a single unit that interfaces with the computer via a single hard drive controller.
The present invention is a device for electronic data storage that can be in the form of a stackable sealed hard drive component. The device of the present invention can comprise a plurality of hard drives, each of which includes an electrical connector and a hard drive connecting means for connecting the hard drives to one another in a stack with a first end and a second end. The hard drives can be contained in a housing having a top section and a bottom section that is hermetically sealed to the top section, such that the housing hermetically seals the hard drives. The first end and the second end of the hard drive stack can be connected to the housing using a housing connecting means. An electrical terminal means can mount the housing directly to a circuit board and a connecting lead can electrically connect the electrical terminal means to the hard drive electrical connectors. A hard drive controller can control at least two of the hard drives. The hard drive controller optionally can control all of the hard drives and can be located inside or outside the housing. The hard drives can be microdrives.
In another embodiment of the invention, the device comprises a plurality of hard drives and a hard drive controller for controlling at least two, or as many as all, of the hard drives. The device can include a housing for containing and hermetically sealing the hard drives. The housing can include a top section and a bottom section that is hermetically sealed to the top section. The hard drive controller can be located inside or outside the housing.
In another embodiment of the invention, the device comprises a plurality of hard drives, each of which includes an electrical connector, a hard drive connecting means for connecting the hard drives to one another in a stack having a first end and a second end, a housing for containing and hermetically sealing the hard drives, and a housing connecting means for connecting the first end and the second end of the hard drive stack to the housing. Each hard drive can include a hard drive electrical connector. The device can include an electrical terminal means for mounting the housing directly to a circuit board and a connecting lead for electrically connecting the electrical terminal means to the hard drive electrical connector.
In another embodiment of the invention, the device comprises at least one hard drive and electrical terminal means for electrically connecting and mounting the hard drive directly to a circuit board. Each hard drive can also include a hard drive electrical connector. The device can include a connecting lead for electrically connecting the electrical terminal means to the hard drive electrical connector.
In yet another embodiment of the invention, the device comprises at least one hard drive and a housing for containing and hermetically sealing the hard drive or hard drives. The hard drives can be microdrives. The housing can include a top section and a bottom section that is hermetically sealed to the top section.
The device of the present invention overcomes the limitations associated with the hard drives known in the art. The device of the present invention provides a hard drive component for electronic data storage that can be mounted directly to a circuit board in the same fashion that other electrical components such as integrated circuits are mounted to circuit boards, thereby saving space. The device of the present invention also provides a hard drive component for electronic data storage that is contained within a hermetically sealed container. Because the housing is hermetically sealed, the air pressure inside the housing remains constant, regardless of the air pressure of the surrounding environment. Therefore, the hard drive component can be used in applications where the environmental air pressure varies. The sealed housing also prevents contamination of the hard drives from the environment by micro-particles such as dust. The device of the present invention also provides a hard drive component for electronic data storage that has increased storage capacity because several hard drives are stacked into a single unit. The resulting stack of hard drives consume less space than would independently installed hard drives. The device of the present invention also provides a hard drive component for electronic data storage in which several hard drives are combined into a single unit that interfaces with the computer via a single hard drive controller, thereby reducing cost and decreasing the physical space the hard drive component consumes.